The Nervous System
What Are the Functions and the Layers of the Meninges?

Layers of the Meninges:
There are three layers that make the meninges. They protect the brain.
meninges.jpg
http://www.google.com/imgres?imgurl=http:www.web-books.com/eLibrary/Medicine/Physiology/Nervous/meninges.jpg&imgrefurl=http://www.web-books.com/eLibrary/Medicine/Physiology/Nervous/Nervous.htm&usg

1.) Dura Mater:
This is the outermost layer of the meninges, closest to the skull. This layer is tough and inflexible, making it able to protect the brain.

2.) Arachnoid:
This is the second and middle layer of the meninges. In some areas, it projects into the sinuses formed by the dura mater. The cerebral spinal fluid is found between this layer and the pia mater. The CSF protects the brain from impact as well as helping the brain remain bouyant.

3.) Pia Mater
This is the innermost layer of the meninges. It adheres closely to the brain.

Types of Hematomas:
A hematoma is an abnormal pooling of blood in the meninges. A hematoma is usually a result of a head injury.

hematoma.jpg

http://www.google.com/imgres?imgurl=http:
mmajunkie.com/dyn/images/fighters/mark-hominick-hematoma.jpg&imgrefurl=http://mmajunkie.com/news/23459/ask-the-fight-doc-should-mark-hominicks-hematoma-prompted-a-stoppage.mma&usg

1.) Subdural Hematoma: Bleeding that accumulates below the dura.

2.) Epidural Hematoma: Bleeding that accumulates in the epidural space outside the dura.

3.) Sub-arachnoid hematoma: bleeding between the arachnoid membrane and pia mater.